Radius conveyor belt with structure for the prevention of pinched fingers

ABSTRACT

A modular conveyor belt formed of rows of belt modules pivotally interlinked by transverse pivot rods and specially adapted for following a curved conveyor path. The modules include a top, product conveying surface and a bottom, sprocket-driven surface. The belt modules have a plurality of first link ends disposed in the direction of travel of the conveyor belt and a plurality of second link ends disposed in the opposite direction. Transverse holes in the link ends are aligned to accommodate a pivot rod. When the link ends of the consecutive rows of side by side modules are intercalated, the pivot rod serves as a hinge pin in a hinged joint between consecutive interlinked rows. To permit the belt to flex sidewise, the openings in the first link ends are slotted longitudinally in the direction of belt travel. In order to prevent fingers from penetrating the grid, the belt modules have a cross-rib with an extended portion in the longitudinal direction designed so as to allow the link ends to undercut the cross-rib when collapsing and to reduce the gap between adjacent modules.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] The present application is a continuation-in-part applicationclaiming priority to U.S. patent application Ser. No. 09/579,090 filedMay 25, 2000, and entitled “Radius Conveyor Belt,” which is incorporatedherein by reference.

FIELD OF INVENTION

[0002] This invention relates to conveyor belts and, more particularly,to modular plastic conveyor belts formed of rows of plastic belt modulespivotally interlinked by transverse pivot rods.

BACKGROUND OF THE INVENTION

[0003] Because they do not corrode, are light weight, and are easy toclean, unlike metal conveyor belts, plastic conveyor belts are usedwidely, especially in conveying food products. Modular plastic conveyorbelts are made up of molded plastic modular links, or belt modules, thatcan be arranged side by side in rows of selectable width. A series ofspaced apart link ends extending from each side of the modules includealigned apertures to accommodate a pivot rod. The link ends along oneend of a row of modules are interconnected with the link ends of anadjacent row. A pivot rod journaled in the aligned apertures of theside-by-side and end-to-end connected modules forms a hinge betweenadjacent rows. Rows of belt modules are connected together to form anendless conveyor belt capable of articulating about a drive sprocket.

[0004] In many industrial applications, conveyor belts are used to carryproducts along paths including curved segments. Belts capable of flexingsidewise to follow curved paths are referred to as side-flexing, turn,or radius belts. As a radius belt negotiates a turn, the belt must beable to fan out because the edge of the belt at the outside of the turnfollows a longer path than the edge at the inside of the turn. In orderto fan out, a modular plastic radius belt typically has provisions thatallow it to collapse at the inside of a turn or to spread out at theoutside of the turn.

[0005] Apertures slotted in the direction of travel of the belt arecommonly provided in the link ends on at least one side of the modulesto facilitate the collapsing and spreading of the belt.

[0006] In applications where greater strength is required radius beltswith a larger pitch are required. These radius belts with a large pitch(≧1.5″) have suffered from the disadvantage that, due to the largerpitch and the need to be collapsible, the grid openings were largeenough to allow the finger of operators to penetrate the grid. Thissituation may lead to injuries.

[0007] What is needed is a modular radius conveyor belt that has a largepitch yet reduces the gap between the links to less than 10 mm toprevent fingers from penetrating the grid.

SUMMARY OF THE INVENTION

[0008] The present invention meets the above-described need by providinga radius belt having belt modules with a cross-rib designed so as toallow the link ends to undercut the cross-rib when collapsing. Themodule has a cross-rib with an extended portion in the longitudinaldirection. The modules include first and second module surfaces, i.e., atop, product-conveying surface and a bottom, sprocket-driven surface. Across-rib extends across the width of each module transverse to thedirection of belt travel. The cross-rib is formed in part by a web andin part by a thin, corrugated strip having a pair of essentiallyparallel walls. The corrugated strip forms a series of regularly spacedalternating ridges and valleys along each wall. Link ends extend outwardfrom the ridges on each wall of the corrugated strip. Each link end hasa leg portion attached at a ridge of the strip and a thick distalportion at the end of the link end distant from the corrugated strip.Transverse holes in the link ends extending from respective walls of amodule are aligned to accommodate a pivot rod. When the link ends ofconsecutive rows of side-by-side modules are intercalated, the pivot rodserves as a hinge pin in a hinged joint between consecutive interlinkedrows. To permit the belt to follow a curved path, the pivot rod openingsin at least one of the link ends extending from one of the walls of thecorrugated strip are slotted longitudinally in the direction of belttravel.

[0009] The belt is driven by engagement of the sprocket tooth with thecurved outside surface of the link ends. The link end engaged by thesprocket tooth is subjected to a compressive force rather than anundesirable tensile force. Thus, the link ends provide pull strength,resistance to belt and sprocket wear, and sprocket drivability. As analternative, a central portion of a link end disposed in the middle beltmodules may also engage with a tooth on the drive sprocket. Because themid modules do not have to collapse fully, they may be formed with athicker and fully straight cross-rib.

[0010] Each wall of the corrugated strip forms a series of archedrecesses with the leg portions of the link ends. The recesses are largeenough to provide room for a thick link end of an interlinked module ofan adjacent row to collapse into the recess or to rotate as belt rowsfan out going around a turn. Because the recesses along one wall overlapin a transverse direction with the recesses along the other wall,additional space for collapsing is provided.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The invention is illustrated in the drawings in which likereference characters designate the same or similar parts throughout thefigures of which:

[0012]FIG. 1 is a top plan view of a radius conveyor belt module of thepresent invention;

[0013]FIG. 2 is a bottom plan view of the belt module of the presentinvention;

[0014]FIG. 3 is an end elevation view of the belt module of the presentinvention;

[0015]FIG. 4 is an end elevation view of the belt module of the presentinvention;

[0016]FIG. 5 is a top perspective view of the belt module of the presentinvention;

[0017]FIG. 6 is a bottom perspective view of the belt module of thepresent invention;

[0018]FIG. 7 is a top plan view of a radius belt of the presentinvention;

[0019]FIG. 8 is a partial detailed view of a section of the belt of FIG.7;

[0020]FIG. 9 is a side elevational view of a belt of the presentinvention engaged with a sprocket and illustrating the gaps betweenadjacent modules.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Referring now to the drawings, FIGS. 1 to 9 show a firstembodiment of a modular belt 20 of the present invention. The portion ofthe modular belt 20 shown is formed from molded plastic modules 23, 26,27 and 29 (FIG. 7). For reference, the direction of belt travel isindicated by arrow 32, however, the belt of the present invention may beconveyed in either direction. A pivot rod 35 (FIG. 7) connects adjacentbelt modules by passing through openings in the modules disposedtransverse to the direction of belt travel.

[0022] As shown in FIG. 1, an exemplary one of the belt module 26 has across-rib 38 supporting a plurality of first link ends 41 and aplurality of second link ends 44. The first link ends 41 are disposed inthe direction of belt travel indicated by arrow 32 and the plurality ofsecond link ends 44 extend opposite the first link ends 41. As will bedescribed in detail hereinafter, the cross-rib 38 is comprised of anupper, transverse stiffening web 47 forming into a lower corrugatedportion 50 (shown in broken lines in FIG. 1). The corrugated portion 50forms a series of ridges 53 and valleys 56 in a sinusoidal manner. Alongwith the transverse web 47 of the cross-rib 38, the ridges 53 extendingtoward the right of FIG. 2 support the first link ends 41 while theridges 53 extending toward the left in the drawing support the secondlink ends 44.

[0023] The first link ends 41 include a leg portion 59 connected throughan angled portion 62 to a distal head portion 65. In a similar manner,the second link ends 44 include a leg portion 68 connected through anangled portion 71 to a distal head portion 74.

[0024] With respect to the orientation shown in FIG. 3, the cross-rib38, which is formed of the stiffening web 47 and the corrugated portion50 (FIG. 2), is comprised of an upper surface 77 extending to andmeeting with opposed left and right walls 80 and 83 which, in turn, meetwith a lower surface 86 of the module. The left wall 80 is comprised ofan upper wall 89, which is part of the stiffening web 47, and extendsdownwardly to a curved wall 92 which forms into a lower vertical wall95. The curved wall 92 and the lower vertical wall 95 are part of thecorrugated portion 50 of the cross-rib 38. The lower vertical wall 95extends to the lower surface 86 of the module which, in turn, extends toand meets with the right vertical wall 83.

[0025] As shown in FIG. 2, the head portion 65 is preferably larger thanthe leg portion 59. Accordingly, the head portion 65 is connected to theleg portion 59 by the angled portion 62. The head portion 65 ispreferably formed with two substantially parallel sides 98 and 101connected by an outer end 104. The corners between the sides 98, 101 andends 104 are preferably radiused to be smooth and to protect theconveyed product from damage.

[0026] An opening 107 is defined between spaced apart sides 110, 113 ofadjacent link ends. At a distal end 116, the ends of adjacent links formthe mouth 119 of the opening 107. At the opposite end 122, the opening107 terminates in the multi-level surface defined by the web 47 andcorrugated portion 50 as described above. The top level of the surface(best shown in FIG. 1) is defined by wall 89 (FIG. 3) of the web 47. Thecorners where the side walls of the link ends 41 meet the straight wall89 of web 47, are also radiused to be smooth and to protect the conveyedproduct from damage.

[0027] In FIG. 2, the bottom level of the surface of cross-rib 38 isdefined by the relatively thin corrugated portion 50 having a pair ofessentially parallel walls 125, 128. The corrugated portion 50 forms theseries of regularly spaced alternating ridges 53 and valleys 56 alongthe cross-rib 38 as described herein.

[0028] Returning to FIG. 1, the straight wall 89 is shown bordering theopening 107. The curved surface defined by corrugated portion 50 isshown in broken lines. The curved surface receives link ends from anadjacent belt module such that the belt 20 is capable of collapsing formovement around a curved path as described in detail herein.

[0029] The plurality of second link ends 44 extend from the belt module26 in the opposite direction from the first link ends 41. The secondlink ends 44 have the same overall shape as the first link ends 41 andare designed to fit into the openings between the first link ends 41such that adjacent belt modules can be intercalated and pivotallyconnected by the pivot rods 35.

[0030] As shown in FIG. 3, the belt module 26 includes a slot 134 thatis disposed through the link ends 41 transverse to the direction of belttravel. The slot 134 extends in the direction of belt travel such thatit is generally oblong. The slot 134 receives the pivot rod 35. Thepivot rod 35 passes through the slots 134 in the first link ends 41 andthrough the openings 137 in the second link ends 44 (as shown in FIG.7). The openings 137 correspond to the shape of the shaft 138 (FIG. 7)of the pivot rod 35 such that the pivot rod 35 is received through theopening 137 but in contrast to slot 134, the pivot rod 35 preferablycannot move in the direction of belt travel inside opening 137. Due tothe oblong shape of slot 134, the pivot rod 35 can pivot inside the slot134 such that the belt 20 is capable of collapsing on one side while theother side fans out due to the pivoting of rod 35 and the nesting of thelink ends 41, 44 and cooperating spaces in the adjacent belt modules.

[0031] In FIG. 4, the last link end 45 of the belt module 26 includes asecond opening 140 disposed around opening 137 to provide forcountersinking a head (not shown) at the end of the pivot rod shaft 138.

[0032] The transverse slot 134 in link ends 41 and the transverseopening 137 in link ends 44 receive pivot rods 35 to connect adjacentbelt modules 23 and 29 as shown in FIG. 7. As shown in FIG. 5, the web47 is coterminous with the top surface 77 of the belt module 26 andterminates at the top of the corrugated portion 50 that defines thespace between adjacent link ends (best shown in FIG. 6).

[0033] The outer ends 104 of the link ends 41 and 44 are radiused in asmooth rounded surface 146. The rounded surface 146 preferably comprisesa rounded surface having a constant radius and provides a drivingsurface for engagement with the drive sprocket 149 as described herein.

[0034] Also, the curvature of the outer ends 104 of the link endsenables the links to clear the web 47 when the adjacent modules collapsealong the edge. The clearance enables the link ends to extend under theweb 47 into the space defined by the corrugated portion 50 (best shownin FIGS. 5-6). In this manner, the web 47 partially hoods the link endswhen the belt 20 collapses. Accordingly, the belt module 26 provides aweb 47 for structural stability while maintaining a corrugated portion50 to allow for recesses that provide maximum space for collapsing thebelt modules around a curved path.

[0035] In FIG. 7, the belt 20 is shown at its maximum lengthwiseextension. For example, the maximum lengthwise extension creates spaces200 bordered by the cross-rib 38, the link ends 44 of module 23 and thelink ends 41 of the adjacent module. In order to prevent small fingersfrom penetrating the belt grid and engaging with a belt support 205(FIG. 9), the top surface 77 of the cross-rib is extended such that theopening 200 described above is less than 10 mm. At the top conveyingsurface, the opening 200 is bordered on one side by upper wall 89. Thespace 200 is also bordered by sides 110, 113, of adjacent link ends 44.The end of space 200 opposite from upper wall 89 is defined by the outerend 104 of link end 41 on the adjacent belt module 26. Also, a portionof the sides 98 and 101 of link end 41 border space 200.

[0036] For belts having a pitch greater than or equal to 1.5 inches, theopenings created in the belt grid may allow for fingers to penetrate thegrid.

[0037] In the present invention, for belts having pitches greater thanor equal to 1.5 inches, extending the upper wall 89 outward from thecross-rib 38 reduces the size of space 200. The upper wall 89 is sizedso that when the belt 20 is fully extended lengthwise the space 200 hascritical opening widths or diameter less than 10 mm. Critical openingwidth or diameter is defined as the distance of the opening across itssmallest dimension.

[0038] The extended upper wall 89 is sized to reduce the size of theopening yet allows the belt 20 to collapse without obstruction. Thecurvature of the link end from the top surface provides for nesting ofthe link end beneath the upper wall 89.

[0039] In FIG. 9, the belt modules 20 are shown driven by the teeth 148on the drive sprocket 149. The drive sprocket 149 is driven by arotating shaft (not shown) as known to those of ordinary skill in theart. A cylindrical member 210, which is representative of a smallfinger, has a diameter of 10 mm. As shown, the space 200 is not largeenough to accommodate the member 210.

[0040] Accordingly, a radius belt 20 suitable for larger pitch (≧1.5″)radius belt applications has been disclosed. The belt 20 has an extendedcross-rib 38 that reduces the space 200 to less than lOmm width so as toprevent fingers of a user from penetrating the belt grid.

[0041] While the invention has been described in connection with certainpreferred embodiments, it is not intended to limit the scope of theinvention to the particular forms set forth, but, on the contrary, it isintended to cover such alternatives, modifications, and equivalents asmay be included within the spirit and scope of the invention as definedby the appended claims.

What is claimed is:
 1. A radius conveyor belt, comprising: a pluralityof belt modules having a plurality of first link ends disposed in thedirection of belt travel and having a plurality of second link endsdisposed in the opposite direction, a cross-rib disposed between thefirst and second link ends and having a web, and a corrugated portiondisposed adjacent to the web, the first and second link ends disposedsuch that a space capable of receiving a link end is formed between eachadjacent link end, the space being open at one end and terminating in anrounded region at the opposite end, the plurality of first link endsbeing offset from the plurality of second link ends such that the firstlink ends align with the space between the second link ends such thatadjacently positioned belt modules are capable of intercalating so thatthe first link ends of one belt module fit into the spaces definedbetween the second link ends of an adjacent belt module, the pluralityof first link ends having a slot defined therein, the slot disposedtransverse to the direction of belt travel and extending in thedirection of belt travel, the plurality of second link ends having atransverse opening defined therein; a pivot rod extending transverse tothe direction of belt travel through the openings in the second link endof one of the plurality of belt modules and extending through theslotted openings in the first link end of an adjacent belt module suchthat the first and second link ends of the adjacent belt modules areintercalated and the adjacent belt modules are interlinked into adjacenthinged rows capable of following a curved path; wherein the web on thecross-rib extends in the direction of belt travel such that, when thebelt is at its maximum extension in the direction of belt travel, aspace bounded by the web, an outer end of the first link end and thesidewalls of second links ends has a diameter less than 10 mm.
 2. Theradius conveyor belt of claim 1, wherein the first and second link endseach have a leg portion with substantially parallel sidewalls.
 3. Theradius conveyor belt of claim 2, wherein the first and second link endseach have a head portion that is wider than the leg portion, the headportion having a pair of substantially parallel sidewalls and anendwall.
 4. The radius conveyor belt of claim 3, wherein a junction ofthe sidewalls and endwall of the head portion is rounded.
 5. The radiusconveyor belt of claim 3, wherein the endwall of the head portion isrounded and connects a top surface of the link end to a bottom surfaceof the link end.
 6. The radius conveyor belt of claim 1, furthercomprising an opening disposed through the belt module from the topsurface to the bottom surface.
 7. The radius conveyor belt of claim 1,wherein the web and corrugated portion form a multilevel surfacedefining the end of the space between adjacent link ends.
 8. A conveyingsystem, comprising: an endless radius conveyor belt, comprising aplurality of belt modules having a plurality of first link ends disposedin the direction of belt travel and having a plurality of second linkends disposed in the opposite direction, the first and second link endsdisposed such that a space capable of receiving a link end is formedbetween each adjacent link end, the space being open at one end andterminating in an rounded region at the opposite end, the plurality offirst link ends being offset from the plurality of second link ends suchthat the first link ends align with the space between the second linkends such that adjacently positioned belt modules are capable ofintercalating so that the first link ends of one belt module fit intothe spaces defined between the second link ends of an adjacent beltmodule, the plurality of first link ends having a slot defined therein,the slot disposed transverse to the direction of belt travel andextending in the direction of belt travel, the plurality of second linkends having a transverse opening defined therein; an intermediateportion disposed between the first and second link ends and having a weband a corrugated portion, the web formed in the center of the beltmodules and disposed such that a first side of the web terminates in afirst surface of the belt module and a second side of the web terminatesadjacent to the corrugated portion, wherein the web on the intermediateportion extends in the direction of belt travel such that, when the beltis at its maximum extension in the direction of belt travel, a spacebounded by the web, an outer end of the first link end and the sidewallsof second links ends has a diameter less than 10 mm.; a pivot rodextending transverse to the direction of belt travel through theopenings in the second link end of one of the plurality of belt modulesand extending through the slotted openings in the first link end of anadjacent belt module such that the first and second link ends of theadjacent belt modules are intercalated and the adjacent belt modules areinterlinked into adjacent hinged rows capable of following a curvedpath; and, a drive sprocket having teeth disposed around the perimeterthereof, the teeth capable of engaging with the rounded endwall of thelink ends to drive the endless conveyor belt around a conveying path;and, wherein the web and corrugated portion form a multilevel surfacedefining the end of the space between adjacent link ends.
 9. Theconveying system of claim 8, wherein the first and second link ends eachhave a leg portion with substantially parallel sidewalls.
 10. Theconveying system of claim 9, wherein the first and second link ends eachhave a head portion that is wider than the leg portion, the head portionhaving a pair of substantially parallel sidewalls and an endwall. 11.The conveying system of claim 10, wherein a junction of the sidewallsand endwall of the head portion is rounded.
 12. The conveying system ofclaim 10, wherein the endwall of the head portion is rounded andconnects a top surface of the link end to a bottom surface of the linkend.
 13. The conveying system of claim 8, further comprising an openingdisposed through the belt module from the top surface to the bottomsurface.
 14. The conveying system of claim 8, wherein the web androunded regions form a multilevel surface defining the end of the spacebetween adjacent link ends.